The Mirage Tank is by itself, unremarkable. Armor is adequate for most situations, but fares poorly against anti-tank weapons and actual combat with other tanks. It does have a respectable laser for a primary weapon. It doesn't really shine until it is deployed with its stealth suit. The tank literally vanishes as long as it is stationary or moves at 50% speed or slower and doesn't engage targets. With its laser, there is no muzzle flash or heavy recoil, and now loud report from a gun. Mirage tanks are ambush hunters and absolutely devastating against lightly armored vehicles and infantry.

The Battlefortress is a monsterous vehicle that exists to prove that the tank isnt out of the fight with the presence of mechs. The BattleFortress mounts a heavy cannon and can transport a platoon of conventional infantry or a squad of power armor infantry into battle. The infantry inside the Battlefortress can use their weapons to fight from inside the giant IFV. The BattleFortress has massive armor and can literally drive over and crush smaller vehicles monster truck style. Mechs are not immune to this, if the BFortress can knock a mech prone, it can drive over it in the next combat turn and crush it, or badly damage it. The main gun is traditionally used with high explosive ammunition and bunker busting rounds for taking out fortifications.

The Wolverine is the workhorse of the western powers, a well rounded mech with an automatic 75mm cannon, supported with beam weaponry and a multi-role direct fire missile launcher. The 75mm gun is highly effective against light and medium armored vehicles and other mechs of similar weight class. The main complaint against the Wolverine is that the main gun is less effective against heavily armored foes, such as Mammoth Tanks, Assault Walkers, and so on.

The Blackjack is a multi-role fire support mech. It is principally armed with two 75mm autocannons. Like the Wolverine's gun, these cannons are capable of rapid fire. Unlike the Wolverine's gun, these 75's are long barrel models are are used as multi-role artillery and flak guns. The Blackjack can lay down accurate artillery fire from several miles away, though the weight of the 75mm HE round isnt the most devastating, it compensates with accuracy and precision. As an AA vehicle, the long barrel 75's can throw up a wall of proximity and flak rounds that are deadly to helicopters, jetpack infantry, and aircraft.

EchoMirage:
I see you're liberally borrowing names for 'Mechs from BattleTech - even the Wolverine's weapon payload is almost identical (except for the medium laser and jump jets).